Apocalypse: God-level Zombie Synthesis System - Chapter 1307 - : Does this answer count as an explanation?

Outer Sect Disciple Chen Yu, assimilates within his body a fiendgod heart.

The heart, is the backbone of life, the human body’s fatal vital point. And it can be said that Chen Yu’s heart is actually his strongest defense point, and permits him to overtake demonic beasts, or divine beasts unlimited potential.

Henceforth, he steps onto the stage and surges forth on a magnificent scale, in a heart-rending mysterious journey.

Talented as a cloud, an unparalleled supreme talent.

10,000 races glorious, cross boundary battles.

Only my heart, eternal!

- Description from Novelupdates

Three years after entering the palace, Yongning Palace’s Yan Shu meiren, has still never met the Emperor.

The palace full of concubines tried to win his favour, only she, immersed in a melon eating system, has no time to spare for him.

How would she know that one day, she actually ate a shockingly big melon——

Yan Shu, “!!! No wonder he never enters the harem!”

Wait…

There seems to be something wrong somewhere… then what did she enter the palace for?!!

The new Emperor, Yu Wen Lan, has two secrets.

Since his ascension to the throne, he has gradually lost his male functions; yet at the same time, he can read minds.

Getting used to seeing their false words and hypocritical faces every day, he grew all the more unfeeling.

That was, until one day, he heard a special heart’s voice——

Yu Wen Lan paused, narrowing his eyes to look in the direction of a delicately pretty and pure looking girl.

Until she ascended to the position of Empress, Yan Shu also didn’t know how she had jumped unreasonably on the Emperor’s bottom line repeatedly, yet had jumped straight in, becoming the first person to be in his heart.

Perhaps, it was just her good luck.

- Description from Novelupdates

Accidentally, she got pregnant.